无口咽侵犯T1～2N0鼻咽癌放射治疗设野的前瞻性研究

目的评价无口咽侵犯的T1-2N0鼻咽癌不同设野放射治疗的近期疗效。方法将56例T1，2NoM0 1992年福州分期鼻咽癌病人随机分为面颈联合野组（A组）和面颈分野组（B组），A组先设面颈联合野和下颈切线野，均照射36Gy后改双耳前野24Gy，鼻前野8—10Gy和颈前切线野14Gy；B组设置双耳前野60Gy，鼻前野8-10Gy，颈前切线野50Gy。结果放疗结束时，鼻咽原发灶消退率A组和B组分别为96.4％和92．9％，两组无显著差异。A、B组2年总生存率分别为89.3％和85．7％。面颈分野组1例发生放射性颈脊髓损伤，两组急性和慢性放射损伤差异均无显著性。结论T1-2N0M0鼻咽癌病人选用面颈联合野或面颈分野，疗效无显著性差异。5年生存率及远期放射损伤情况有待进一步观察。     

鼻咽癌双侧茎突后区受侵放疗计划改进

针对常规方案为茎突后区补量不合理之处,提出改进方案,探讨如何在脊髓、晶体等敏感器官不超过耐受剂量的同时,满足茎突后区的剂量要求,以期提高鼻咽癌的局部控制率.选择双侧茎突后区受侵的局部晚期鼻咽低分化鳞癌病人1例,在常规方案照射至50Gy后.施行三维适形放射治疗,着重讨论在后程三维推量阶段如何设置照射野及分配剩余的20Gy;计划评价工具为剂量-体积直方图统计表并考察茎突后区剂量.鼻咽层面、颅底及以上层面剂量分布满意,90%以上等剂量曲线包绕大部分靶区,茎突后区剂量考察点所受剂量为6405cGv,正常组织剂量没有超过最大限值.该方案可以提高靶区覆盖度,对茎突后区剂量有明显改善.     

鼻咽癌咽旁侵犯患者的远期疗效分析

目的 通过对鼻咽癌咽旁侵犯患者的远期疗效的分析，为合理的设野和临床分期提供依据。方法 对1984年10月至1989年9月收治的经病理、CT检查诊断有咽旁侵犯的120例鼻咽癌患者，采用常规分段放射治疗。鼻咽原发灶设两耳前野为主，部分辅以鼻前野。鼻咽肿瘤总剂量为68～78Gy，照射34～39次／72～85天。颈部根治性肿瘤总剂量为60～68Gy，照射30～34次／72～76天；预防剂量为50Gy。全部病例5年随访率为100．0％，10年随访率为95．0％。结果 茎突前区和茎突后区受侵犯者5年生存率分别为66．1％和44.8％，10年生存率分别为37．1％和25．9％；颈部淋巴结Ⅱ、Ⅲ期10年生存率分别为35．6％和28．0％；2年内鼻咽复发率分别为19．4％和44．8％。茎突前区咽旁侵犯同时伴有颅底骨质破坏、颅神经损害和口咽侵犯的发生率分别为6．5％、6．5％和11．3％，而茎突后区分别为19．0％、25．9％和36．2％。结论 咽旁侵犯是影响鼻咽癌预后的重要因素，然而，不排除因当时技术条件受限对预后的影响。     

鼻咽癌茎突后区受侵程度和放疗计划设计

许多学者针对茎突后区受侵时的放射治疗设计进行了探讨,但文献中缺乏茎突后区受侵程度的测量和分析,从而存在着如何划定靶区,如何选择剂量参考点等问题。关于颈分割野对茎突后区的剂量贡献问题也尚无定论。使用扩大鼻前野、扩大耳前野、不规则面颈联合野后确实在一定程...     

N2-3期鼻咽癌下颈锁骨上区照射中间设置不同宽度铅挡块的剂量学研究

背景与目的:N2-3期鼻咽癌常规照射时,需设置中间挡铅的前切线野照射下颈锁骨上淋巴引流区,目前对于中间铅挡块宽度仍有不同的做法,本研究通过应用三维治疗计划系统(three-dimensional treatment planning system,3D-TPS)对前切线野照射下颈锁骨上区的剂量分布进行分析.探讨合适宽度的铅挡块.方法:选取初治N2-3期鼻咽癌患者10例,采用3D-TPS设计照射方案.每例患者均采用逐步缩野照射技术.下颈锁骨上区均设置单前切线野,前40 Gy中间分别采用铅挡0 cm(A方案)、2.1 cm(B方案)、2.5 cm(C方案)、3.0 cm(D方案),之后中间均挡3.0 cm 4种方案.每例患者的4种方案照射剂量均相同.比较4种照射方案的靶区及主要危及器官的受照体积和剂量.结果:(1)4种方案下颈锁骨上亚临床病灶区(PTV50a)的高剂量区覆盖率(V95、V90)比较:A方案(82.44%、87.89%)优于B方案(78.21%、84.03%)、C方案(77.10%、82.68%)、D方案(73.80%、77.50%)(P＜0.05);B方案、C方案好于D方案(P＜0.05);B方案与C方案比较无统计学意义(P＞0.05).而对于原发灶大体肿瘤区(PTVnx)、颈部转移淋巴结(PTVnd)、原发灶周围高危区(PTVnx60)、转移淋巴结周围高危区(PTVnd60)及环状软骨以上的亚临床病灶区(PTV50b)的V95、V90,4种方案之间比较差异均无统计学意义(P＞0.05).(2)4种方案脊髓、喉的受照剂量无统计学意义;甲状腺、食管、气管的受照剂量(D50):A方案(49.47、44.52、44.18 Gy)高于B方案(41.95、8.41、10.16 Gy)、C方案(38.73、7.03、8.55 Gy)、D方案(26.82、5.63、7.60 Gy)(P＜0.05);B方案、C方案均高于D方案(P＜0.05);B方案、C方案比较无统计学意义(P＞0.05).(3)正常组织并发症发生率(NTCP)的比较:甲状腺的NTCP,A方案(7.9%)高于B方案(4.8%)、C方案(4.3%)、D方案(3.0%)(P＜0.05);B方案、C方案均高于D方案(P＜0.05);B方案、C方案之间比较无统计学意义(P＞0.05).其余主要危及器官的NTCP,4种方案比较差异无统计学意义(P＞0.05).结论:在不明显增加主要危及器官受照剂量的情况下,A方案有最优的下颈锁骨上区亚临床病灶高剂量区覆盖率,D方案最差;行下颈锁骨上区照射时,我们推荐前40 Gy中间不设铅挡块,之后选用个体化铅挡块.对于头颈部摆位误差小的单位,建议采用铅挡块宽度≥2.1 cm、≤2.5 cm.     

制订新的鼻咽癌外照射规范的建议

一、体外放疗常规中存在的不足1．不符合靶区全照射原则近年来对包括咽旁照射设计进行了不少讨论，常规耳前野不能保证茎突后区获得足够剂量，采用耳后野（向前倾斜）补充茎后区＿眼下野补充鼻腔或茎突前区的方法都会将靶区分割开来照射，而且咽分间隙上自颅底、下连颌下间隙，仅考虑鼻咽某一平面的剂量分布是不够全面的。在多数情况下（L、几）鼻咽原发肿瘤、咽旁浸润、口咽侵犯和颈淋巴结转移灶实际上是一个“连续靶区”，因为鼻咽癌颈淋巴结转移率高达60％－85％，其中84％病例有咽旁间隙侵犯，初诊病例CT的咽旁侵犯率可高达65％－～－…     

鼻咽癌不同分割方法治疗近期疗效

1987年7月至1988年7月收治120例鼻咽癌患者,随机分威连续组(A),超分割组(B),分段组(C),每组40例。三组患者性别、年龄基本一致。病理鳞癌112例,泡状核细胞癌3例,未分化癌5例。临床分期Ⅱ期17例,Ⅲ期55例,Ⅳ期48例。 原发灶用~(60)C_o照射,设双耳前野(6—7X6—7cm)和前鼻野,倘CT示侵犯茎突后区加耳后野。剂量A、     

CT检查对鼻咽癌设野的影响

选取1991年7月～1992年6月单纯放疗的鼻咽癌病人120例,分析其放疗前CT图像,我们认为鼻咽癌累及咽旁间隙后区、口咽及前区完全填塞时有下行性生长倾向,最好采用面颈联合野;累及鼻腔者有向前上生长的倾向,鼻前野上半要包及后组筛窦;累及颅底者,要从入侵路径加量;累及前组颅神经者,多无颅底破坏,加量野可比正常颅底野低,以减少颅内受量,累及后组颅神经者,均有后区受累,设野要包及后区;为包及茎突内软组织。鼻前野面积最好采用7cm×7cm。     

基于临床经验的局部晚期鼻咽癌互补分野加量照射的改进方案

目的探讨颅底、后颅窝和茎突后区广泛C形侵犯局部晚期鼻咽癌互补分野同期加量照射(SF-SBI)分割剂量的合理设置、设野的优化和应用时机。方法选取2004年1月至2008年6月中山大学肿瘤防治中心收治的局部晚期NPC患者6例,分别采用分割剂量为2.3~2.7Gy/次的不同SF-SBI方案,用剂量体积直方图比较加量照射肿瘤靶区(BTV)、原发肿瘤计划靶体积(PTVnx)和危及器官(OARs)的剂量学特点差异,评价其临床疗效及并发症。结果全组BTV的平均剂量(Dmean)为73.8~76.2Gy,95%处方剂量所包含的靶体积百分数(V95%)为95.8%~99.9%。PTVnx的Dmean为70.3~75.9Gy,V95%为96.0%~99.9%。靶区中不存在大于80Gy的体积。PTV1和PTV2的V95%分别为98.8%~99.9%和98.9%~99.9%。脑干的50、60Gy所包含的体积百分数(V50、V60)和33%体积所受照射的最大剂量(D33)分别为13.2%~46.3%、2.6%~12.8%和23.8~53.9Gy。同侧颞叶的Dmean、D33和V60分别为23.8~32.2Gy、26.4~39.2Gy和19.5%~25.7%。患者A、B、C同侧颞叶的百分体积分别为9.5%、32.2%和28.7%。同侧颞颌关节的Dmean和D50分别为69.1~76.2Gy和62.2~69.8Gy。随访时间3.5~7年。除患者A为部分缓解(PR)外,其余患者均在放疗中或放疗后获得完全缓解(CR),所有患者均未出现肿瘤局部进展或复发。无1例患者出现脑干放射损伤。采用较大分割剂量(2.4~2.7Gy/次)的患者分别出现了放射性脑病、后组脑神经损伤和严重的张口困难。结论从放疗开始即对BTV和大部分GTV采用2.3Gy/次分割剂量进行照射改进的SF-SBI适形放射治疗计划,以及根据肿瘤实际退缩情况个体化缩小后程放疗射野的优化理论,为局部晚期NPC实施个体化放疗提供了新的技术参考。     

鼻咽癌咽旁受侵不同射野放射治疗长期疗效比较

目的评价鼻咽癌咽旁受侵不同射野放射治疗的长期疗效。方法从１９８８年３月至１９９２年３月，经ＣＴ诊断鼻咽癌咽旁受侵的病人１０１例。所有病人均经病理确诊，被随机分为２个组。一组采用面颈联合野，另一组采用双耳前野加面前野。鼻咽部外照射总肿瘤量均为ＤＴ６８～７２Ｇｙ，照射３４～３６次，６８～７２周。所有病例均随访５年以上。生存曲线按寿命表法计算后绘制，经ｌｏｇ－ｒａｎｋ检验。结果２个组生存曲线比较：面颈联合野组高于非面颈联合野组（Ｐ〈０．０５）；无复发生存曲线比较：面颈联合野组显著高于非面颈联合野组（Ｐ〈００１）。咽旁茎突后区受侵，面颈联合野放射治疗的生存曲线明显高于非面颈联合野（Ｐ〉００５）；单纯茎突前区受侵的病人，面颈联合野与非面颈联合野放射治疗的生存曲线差异无显著意义（Ｐ〉００５）。非面颈联合野组发生１例放射性颈脊髓损伤，２个组急性和慢性放射损伤差异无显著意义。结论对鼻咽癌咽旁受侵的病人宜选用面颈联合野放射治疗。     

影响N0期鼻咽癌放射治疗后颈淋巴结复发因素分析

目的分析颈淋巴结阴性(N0)鼻咽癌放射治疗后颈淋巴结复发的影响因素。方法采用Logistic回归方法回顾性分析接受放射治疗的N0期鼻咽癌211例复发因素。结果211例N0期鼻咽癌放射治疗后49例复发。采用面颈联合野放射治疗,上颈预防剂量>50 Gy比面颈分野上颈剂量50 Gy者颈淋巴结复发率低（t=12.93,P=0.000)。咽旁间隙受侵,T分期高,颈淋巴结复发率高（t=14.91,P=0.001及t=8.78,P=0.003)。全颈预防照射比单纯上颈预防照射的下颈复发率低（χ     

鼻咽旁区插植配合体外放射治疗鼻咽癌

目的探讨鼻咽旁区插植近距离放射治疗技术在鼻咽癌治疗中的作用。方法初治鼻咽癌患者体外照射56～70Gy（T2期56～60Gy,T3期66～70Gy）后复查CT或MRI发现鼻咽旁区残留病例67例,以腔内+鼻咽旁区插植放射治疗增量,咽旁区在模拟机引导下插入1～4根施源管,采用荷兰核通公司生产的192Ir高剂量率近距离治疗机,放射剂量2.5～4.0Gy/次,2次/d,间隔>6h,总剂量12～20Gy,3～4?d完成。插植组与同期的类似病例（67例）配对进行研究。结果鼻咽旁区插植组和对照组的3年生存率分别为92.4%,84.5%（P>0.05);3年无局部复发生存率分别为97.0%、76.4%（P<0.05);3年无远地转移生存率分别为76.6%、69.1%（P>0.05)。鼻咽旁区插植组的晚期放射反应如口干、张口困难发生率均低于对照组。结论鼻咽旁区插植放射治疗可以显著提高鼻咽癌咽旁区残留的局部控制率,拓宽了鼻咽癌近距离放射治疗的适应证,是一种有效的补充治疗手段。     

鼻咽癌常规放疗面颈联合野照射的剂量学研究

目的 利用CT模拟机定位技术及治疗计划系统分析鼻咽癌常规放疗面颈联合野照射时肿瘤靶区及颅底剂量欠量问题,并分析采用不同处方剂量点造成的靶区剂量分布差别.方法 选择11例接受常规放疗的首程鼻咽癌患者,普通模拟机定位,将通过科查房的面颈野边界应用细铅丝在面罩上标记,然后在CT模拟机上采取和普通模拟机定位相同的治疗体位及固定方式进行扫描,获取的图像通过网络系统传输至治疗计划系统.由医生在数字莺建图像上根据细铅丝的位置复制出面颈联合野,同时在横断面上逐层勾画鼻咽原发肿瘤GTV及照射野内的蝶骨体、斜坡等靶区.取两个处方剂量点分别位于第1颈椎前(代表鼻咽深度)和第3颈椎前(代表上颈深度).按临床要求以处方剂量点36 Gy分18次为面颈联合野的处方剂量,由计划系统分别计算原发肿瘤及颅底的剂量.结果 以鼻咽深度为处方剂量点时,95%体积的GTV实际受量为33.31～35.54 Gy,中位值为34.83 Gy;95%体积的颅底实际受量为17.76～34.60 Gy,中位值为30.28 Gy.当以上颈深度为处方剂量点时,95%体积的GTV实际受量为31.43～33.36 Gy,中位值为32.44 Gy;95%体积的颅底实际受量为16.52～32.60 Gy,中位值为28.52 Gy.结论 鼻咽癌常规放疗采用面颈联合野无论采用鼻咽还是上颈部为处方剂量计算深度均会造成GTV及颅底剂量低于处方剂量,后者尤为明显.提示临床实施常规放疗时应以鼻咽深度为处方剂量点,同时应结合临床情况酌情考虑对颅底受侵患者疗终给予适当补量.     

Treatment outcomes and late complications of 849 patients with nasopharyngeal carcinoma treated with radiotherapy alone

PURPOSE: The objective of this study was to describe the treatment outcomes and treatment-related complications of nasopharyngeal carcinoma (NPC) patients treated with radiotherapy alone. METHODS AND MATERIALS: Retrospective analysis was performed on 849 consecutive NPC patients treated between 1983 and 1998 in our institution. Potentially significant patient-related and treatment-related variables were analyzed. Radiation-related complications were recorded. RESULTS: The 5-year overall and disease-free survival rates of these patients were 59% and 52%, respectively. Advanced parapharyngeal space (PPS) invasion showed stronger prognostic value than PPS invasion. Multiple neck lymph node (LN) involvement was demonstrated to be one of the most powerful independent prognostic factors among all LN-related parameters. External beam radiation dose more than 72 Gy was associated with significantly higher incidence of hearing impairment, trismus, and temporal lobe necrosis. CONCLUSIONS: We recommend that the extent of PPS should be clarified and stratified. Multiple neck LN involvement could be integrated into the N-classification in further revisions of the American Joint Committee on Cancer stage. Boost irradiation is not suggested for node-negative necks. For node-positive necks, boost irradiation is indicated and a longer interval between initial and boost irradiation would reduce the incidence of neck fibrosis without compromising the neck control rate.     

Treatment planning and delivery of intensity-modulated radiation therapy for primary nasopharynx cancer

PURPOSE: To implement intensity-modulated radiation therapy (IMRT) for primary nasopharynx cancer and to compare this technique with conventional treatment methods. METHODS AND MATERIALS: Between May 1998 and June 2000, 23 patients with primary nasopharynx cancer were treated with IMRT delivered with dynamic multileaf collimation. Treatments were designed using an inverse planning algorithm, which accepts dose and dose-volume constraints for targets and normal structures. The IMRT plan was compared with a traditional plan consisting of phased lateral fields and a three-dimensional (3D) plan consisting of a combination of lateral fields and a 3D conformal plan. RESULTS: Mean planning target volume (PTV) dose increased from 67.9 Gy with the traditional plan, to 74.6 Gy and 77.3 Gy with the 3D and IMRT plans, respectively. PTV coverage improved in the parapharyngeal region, the skull base, and the medial aspects of the nodal volumes using IMRT and doses to all normal structures decreased compared to the other treatment approaches. Average maximum cord dose decreased from 49 Gy with the traditional plan, to 44 Gy with the 3D plan and 34.5 Gy with IMRT. With the IMRT plan, the volume of mandible and temporal lobes receiving more than 60 Gy decreased by 10-15% compared to the traditional and 3D plans. The mean parotid gland dose decreased with IMRT, although it was not low enough to preserve salivary function. CONCLUSION: Lower normal tissue doses and improved target coverage, primarily in the retropharynx, skull base, and nodal regions, were achieved using IMRT. IMRT could potentially improve locoregional control and toxicity at current dose levels or facilitate dose escalation to further enhance locoregional control.     

Spinal cord dose reduction using an anterior 13 MeV electron field situated between a split anterior 60Co supraclavicular field

As part of the treatment for lymphoma, disease involving the supraclavicular region has been treated with megavoltage 60Co photons to a midline dose of 30 to 45 Gy through an anterior involved field and a supplementary posterior field when necessary. The spinal cord was shielded with a 5 cm lead block during treatment to the posterior field. A typical 40 Gy treatment results in a dose to the lower cervical and upper thoracic spinal cord in the range of 22 to 26 Gy, a level that could compromise subsequent mediastinal treatment in the event of a relapse. To reduce this cord dose, the midportion of the anterior supraclavicular 60Co To reduce this cord dose, the midportion of the anterior supraclavicular 60Co field was replaced with a high-energy (13 MeV) electron port, which reduces the dose to the cord to below 6 Gy in the average adult patient. This modification of the routine supraclavicular treatment allows greater flexibility in future treatment in the event of a mediastinal relapse.     

Posterior fossa boost in medulloblastoma: an analysis of dose to surrounding structures using 3-dimensional (conformal) radiotherapy

PURPOSE: The purpose of this study was to compare three different techniques of delivering the posterior fossa boost in patients with medulloblastoma. METHODS AND MATERIALS: Five patients underwent CT simulation for treatment planning of the posterior fossa boost. For each slice, the posterior fossa was contoured in addition to the cochlea, non-posterior fossa brain, pituitary gland, mandible, parotid glands, thyroid gland, pharynx, and cervical spinal cord. For each patient, plans for three techniques of delivering the posterior fossa boost were compared. Technique A utilized parallel-opposed lateral fields using bony landmarks (2-dimensional radiotherapy); the other two techniques were planned using 3-dimensional radiotherapy. Technique B utilized a pair of coplanar wedged posterior oblique beams, whereas Technique C utilized a pair of posterior oblique fields and a vertex field. Dose-volume histograms (DVH) were obtained for each of the organs contoured and for each technique and patient. The maximum, minimum, and mean dose to each organ were determined using the DVH program in our treatment planning system. RESULTS: In 3 of 5 patients, the planning target volume (PTV) was not included in the treatment field with Technique A. The cochlea received 100%, 50%, and 42% of the prescribed posterior fossa dose using Techniques A, B, and C respectively. The mean dose to the non-posterior fossa brain was highest with Technique C, intermediate with Technique A, and lowest for Technique B. The mean dose to the non-posterior fossa brain with Technique B was comparable to the mean non-posterior fossa brain dose delivered using parallel-opposed lateral fields based on the CT definition of the PTV. Likewise, mean dose to the pituitary gland was lowest for Technique B. Both Techniques B and C were associated with a higher mean dose to the thyroid gland, mandible, parotid glands, and pharynx. CONCLUSIONS: The use of Technique B minimized the radiotherapy dose to the cochlea, pituitary gland, and non-posterior fossa brain. Contrary to what one may expect, conformal radiotherapy using Technique B did not deliver a higher dose to the non-posterior fossa brain over standard parallel-opposed lateral fields. Other advantages of conformal techniques B and C over 2-dimensional radiotherapy are the inclusion of the PTV in all patients and a lower mean dose to the pituitary gland. The main disadvantage of conformal Techniques B and C employed in our patients is a higher mean dose to the thyroid gland and other tissues in the neck.     

鼻咽癌外照射加腔内近距离超分割推量照射的远期疗效分析

背景与目的:鼻咽癌的后装治疗一般采用鼻咽腔内治疗的方法进行推量照射,适用于局部早期鼻咽癌.福建省肿瘤医院率先开展鼻咽旁插植技术,无颅底破坏的局部晚期鼻咽癌采用后装治疗推量照射.本文分析腔内后装推量照射的远期疗效,探讨常规外照射的合适剂量配合后程超分割后装推量照射的临床价值.方法:1998年1月～2002年12月体外照射加腔内后装超分割推量放射治疗鼻咽癌患者352例,体外常规放射治疗50～70 Gy后进行腔内近距离超分割推量照射,外照射后咽旁间隙肿瘤残留者配合咽旁区插植放疗.采用个体化鼻咽腔内施源器,超分割照射每次2.5～3.0 Gy,2次/天,间隔6 h,总剂量5～32 Gy,中位剂量17 Gy.结果:本组l、2、3、5年生存率分别为97.0%、91.3%、87.6%、84.7%.总体5年生存率Ⅰ、Ⅱ期88.2%,Ⅲ、Ⅳ期79.2%(log-rank检验,P=0.016);总体局控率Ⅰ、Ⅱ期94.1%,Ⅲ、Ⅳ期91.7%(log-rank检验,P＞0.05).后组颅神经损伤32例(9.4%).结论:鼻咽腔内后装联合咽旁间隙捅植近距离放射治疗鼻咽癌取得良好的局控率和生存率,局部晚期鼻咽癌取得与早期鼻咽癌类似的局控率,咽旁间隙受累者咽旁插植增加颈动脉鞘区照射剂量,后组颅神经损伤发生率较高.     

A simplified alternative to orthogonal field overlap when irradiating a tracheostomy stoma or the hypopharynx

Orthogonal field arrangements are usually employed to irradiate a tumor volume which includes a tracheostomy stoma or the hypopharynx. This approach may produce a significantly greater dose than intended to a small segment of the cervical spinal cord because of field overlap at depth from divergence of the beams. Various sophisticated approaches have been proposed to compensate for this overlap. All require marked precision in reproducing the fields on a daily basis. We propose a simplified approach of initially irradiating the entire treatment volume by saterior and posterior opposed fields. Opposed lateral fields that exclude the spinal cord would then provide local boost treatment. A case example and computer-generated isodose curves are presented.